So I'm on the highway right now and am feeling skeptical about my mpgs.
Before I started my trip I filled my tank completely up, the needle was up to the F on my fuel gauge. I also reset the trip a miles before I left the gas station. I've gone only 45.5 miles and the as needle is below the thick white line at the top of the gauge.
The only thing I can think of that would affect my mileage is the ram air intake I have. That's the only performance mod I have. I've been keeping my speed around 72mph. Is this normal gas consimption? I apologize of this is a dumb post.

 

Well that is not a accurate way to tell gas consumption, the short ram doesn't effect your gas mileage unless your always on the throttle just cause you want to hear the sound. MY car when full doesn't even go above or touch the white full line, your best bet to know the true consumption is but filling tank then driving 200 or so miles and filling again and do the math. by just watching the needle wont tell you anything. As far as gas do you use 100% gas? 91/93? these factors make a difference as well...

 

I'm thinking that since a lot of gas isn't 100% gasoline is what's making my mileage so low. I'd assume the EPA does ratings based on true gasoline, not the E15 some gas is now, and that's why I always stay around 19MPG instead of at least consistent low 20s (I use Fuelly to track my fill-ups), along with driving style and route characteristics. As to the OP, I usually notice the mileage when I hit the first line and I usually get to 50 miles if I am all highway with barely any stopping. Tack miles traveled on the trip odometer, or the full odometer, divided by gallons used to consistently completely fill the tank a few times to get an average on the economy your car is getting. I'm also wondering if changing my spark plugs would help out with my mileage too, but that won't happen until the spring now since it's starting to get cold in NJ.

 

I just purchased a 2000 GLE and I'm starting to check the gas mileage in order to see it's condition.

When I filled up the needle was pegged well above the F. I'm not sure if I trust the needle.

I zero'd out the trip odo and I'll just drive like normal to see how it turns out.

I did put 93 in it (was almost empty when I bought it).

How would I know if the timing is not great for someone possibly using bad gas? In another car I own, you pull a fuse to reset the computer and let it re-calc timing based on the gas currently in the tank. Do I need to do this for the Maxima? Disconnect the battery for a certain amount of time maybe?

 

http://forums.maxima.org/7983009-post2.html

I get 24 +/- 0.5 MPG on a typical tank. Elevation climb and decent of 2000', Approx 50/50 City/Rural highways. I never base it on where the needle is. Just good ol' elementary math. I suggest you do the same.

 

how the heck do you guys get such good mileage?

Due to o2 sensor dying I'm getting ~16 mpg but usually 20-21 mpg

 

OP yeah that is no way to gauge your "gas consumption", do the proper math

george - besides regular maintenance (plugs, fuel filter etc), or modifications that negatively effect mpg (heavy aftermarket wheels) it really all comes down driving style and technique.

Anyone can increase MPG by 30% on just driving habits alone

I can get highway MPG in the city just as easily as highway MPG on the highway

 

I don't have o2 señora and I get 24-28. Now what

 

you dont have any O2s? Or you deleted the downstream ones which dont really do anything anyway?

 

but I've got the secondaries plugged into the primary port, with no primaries at all.

 

What is the point of that? I dont understand deleting the primaries. I know they are somewhat worthless being narrowband but

 

Plain & simple, the primaries didn't reach the port, and I didn't feel like extending the wires. And the secondaries did reach.

Easiest solution for me.

 

+1

 

makes no sense to me, but to each his own.

A bad O2 sensor can cause poor mileage. Picture this, the sensor reading has drifted in its old age so now the 14.7 target is actually 13.7. That will have an impact on your mileage. If the sensor is just not connected like you two have, the ECU obviously isnt going to use its reading to target a specific AFR. As is frequently the case, a bad sensor is worse than no sensor.

 

I took them out during some engine work. Forgot them. Threw a CEL went looking for te issue and found what I did. I never put them back. My car runs fine and I still get like 350-375 miles to the tank. To each their own. You want yours in and I have no reason to put mine back.

 

I really couldn't care less about oxygen sensors but since I've got them might as well use them. FYI I was getting 425 and above each tank when I was still driving the max so maybe those sensors really are affecting your mileage?

 

Nope. Never got 400 miles to the tank anyway. Best I ever got was 387 miles to the tank all highway.

 

If the primaries are DC'd or dead, or in any state of fault, the car then proceeds to read the secondary O2's for primary target AFR. It's been this way since 40k miles (137.5k now), circa 2004.

My AFR is fine @ idle, WOT, etc. I've also got 440's and a 4" intake. And it was fine even before the MAF upscaling.

I have some primaries that I'm going to plug back in, when I get a chance.

 

Update on my gas mileage: I was able to drive 369.2 miles on 15.001 gallons of gas for 24.61mpg. Mixed driving about 65% highway, 35% city. I'm going to still be collecting data to see how it goes.

 

My 3.0 gets about 400mi per tank all highway (camping trips)
and 300mi mixed 50/50 depending if A/C is on.

A/C really eats up the gas.
In the summer I had it blowing all the time and got about 270-280mi.

Tires are taller then stock so it should be more mileage but it's close.